/* ───────────────────────────────────────────────────────────
   chdl · prestige theme — shared across landing + sub-pages.
   Mirrors the in-app PrestigeTheme: #050505 background, white
   text, 2pt sharp corners, italic serif headlines, kerned
   uppercase labels.
   ─────────────────────────────────────────────────────────── */

:root {
    --bg: #050505;
    --bg-elev: #0d0d0d;
    --fg: #ffffff;
    --fg-secondary: rgba(255, 255, 255, 0.7);
    --fg-tertiary: rgba(255, 255, 255, 0.45);
    --glass-fill: rgba(255, 255, 255, 0.05);
    --glass-stroke: rgba(255, 255, 255, 0.12);
    --divider: rgba(255, 255, 255, 0.08);

    --accent-red: #B5545C;
    --accent-gold: #C8A861;
    --accent-purple: #9B7CB8;

    --serif: "Iowan Old Style", "Charter", "Cambria", Georgia, "Songti SC", serif;
    --sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC",
            "Helvetica Neue", "Source Han Sans CN", "Noto Sans CJK SC", sans-serif;

    --max-w: 1180px;
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    padding: 0;
    background: var(--bg);
    color: var(--fg);
    font-family: var(--sans);
    font-size: 16px;
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

::selection { background: rgba(255, 255, 255, 0.18); }

a {
    color: var(--fg);
    text-decoration: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.25);
    transition: border-color 0.15s ease, opacity 0.15s ease;
}
a:hover { border-color: var(--fg); }
a.bare { border: none; }

/* ── Typography helpers ─────────────────────────────────── */

.label {
    font-family: var(--sans);
    font-size: 10px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.3em;
    color: var(--fg-secondary);
}

.serif-display {
    font-family: var(--serif);
    font-style: italic;
    font-weight: 300;
    line-height: 1.05;
    letter-spacing: -0.01em;
}

.cn-display {
    font-family: var(--sans);
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -0.01em;
}

.dot-rule {
    display: inline-flex;
    align-items: center;
    gap: 0.6em;
    color: var(--fg-secondary);
    font-size: 13px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
}
.dot-rule::before,
.dot-rule::after {
    content: "";
    width: 2.4em;
    height: 1px;
    background: var(--fg-tertiary);
}

/* ── Layout ─────────────────────────────────────────────── */

.container {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 28px;
}

main { padding-bottom: 64px; }

/* ── Top nav ────────────────────────────────────────────── */

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 22px 28px;
    max-width: var(--max-w);
    margin: 0 auto;
}
.nav__brand {
    font-family: var(--serif);
    font-style: italic;
    font-size: 22px;
    border: none;
    letter-spacing: -0.01em;
}
.nav__links {
    display: flex;
    gap: 24px;
    font-size: 13px;
    color: var(--fg-secondary);
}
.nav__links a {
    color: var(--fg-secondary);
    border: none;
}
.nav__links a:hover { color: var(--fg); }

/* ── Hero ───────────────────────────────────────────────── */

.hero {
    padding: 64px 0 96px;
    text-align: center;
}
.hero__icon {
    width: 112px;
    height: 112px;
    border-radius: 24px;
    margin: 0 auto 32px;
    display: block;
    box-shadow:
        0 18px 48px rgba(0, 0, 0, 0.6),
        0 2px 8px rgba(0, 0, 0, 0.5);
}
.hero__kicker { margin-bottom: 28px; }
.hero__title {
    font-size: clamp(56px, 9vw, 132px);
    margin: 0 0 18px;
}
.hero__cn {
    font-size: clamp(28px, 4vw, 48px);
    color: var(--fg);
    margin: 0 0 28px;
}
.hero__lede {
    max-width: 640px;
    margin: 0 auto 40px;
    font-size: 17px;
    color: var(--fg-secondary);
    line-height: 1.65;
}
.hero__cta {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 22px;
    border: 1px solid var(--glass-stroke);
    background: var(--glass-fill);
    border-radius: 2px;
    font-size: 14px;
    letter-spacing: 0.04em;
    color: var(--fg);
    transition: background 0.2s ease, transform 0.2s ease;
}
.hero__cta:hover {
    background: rgba(255, 255, 255, 0.09);
    transform: translateY(-1px);
}
.hero__cta-sub {
    display: block;
    margin-top: 12px;
    font-size: 11px;
    letter-spacing: 0.25em;
    text-transform: uppercase;
    color: var(--fg-tertiary);
}

/* ── Numbered editorial sections (mirrors in-app screenshots) ─ */

.chapter {
    padding: 96px 0;
    border-top: 1px solid var(--divider);
}
.chapter__grid {
    display: grid;
    grid-template-columns: 1.05fr 1fr;
    gap: 64px;
    align-items: center;
}
.chapter:nth-child(even) .chapter__grid {
    grid-template-columns: 1fr 1.05fr;
}
.chapter:nth-child(even) .chapter__copy { order: 2; }
.chapter:nth-child(even) .chapter__shot { order: 1; }

.chapter__copy { max-width: 520px; }
.chapter__num {
    display: inline-block;
    margin-bottom: 18px;
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 0.32em;
    text-transform: uppercase;
}
.chapter--01 .chapter__num { color: var(--accent-red); }
.chapter--02 .chapter__num { color: var(--accent-gold); }
.chapter--03 .chapter__num { color: var(--accent-purple); }

.chapter__title {
    font-size: clamp(34px, 4vw, 52px);
    margin: 0 0 14px;
    color: var(--fg);
}
.chapter__subtitle {
    font-size: 13px;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--fg-secondary);
    margin-bottom: 24px;
}
.chapter__body {
    font-size: 16px;
    color: var(--fg-secondary);
    line-height: 1.7;
}
.chapter__body p { margin: 0 0 14px; }
.chapter__body strong { color: var(--fg); font-weight: 600; }

.chapter__shot {
    display: flex;
    justify-content: center;
}
.chapter__shot img {
    width: 100%;
    max-width: 320px;
    height: auto;
    border-radius: 2px;
    box-shadow:
        0 28px 70px rgba(0, 0, 0, 0.55),
        0 4px 12px rgba(0, 0, 0, 0.45);
}

/* ── Feature grid ───────────────────────────────────────── */

.features {
    padding: 96px 0;
    border-top: 1px solid var(--divider);
}
.features__head { text-align: center; margin-bottom: 56px; }
.features__head .label { display: block; margin-bottom: 12px; }
.features__head h2 {
    font-size: clamp(32px, 4vw, 46px);
    margin: 0;
}
.features__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 18px;
}
.feature {
    padding: 26px;
    background: var(--glass-fill);
    border: 1px solid var(--glass-stroke);
    border-radius: 2px;
}
.feature__label {
    font-size: 10px;
    font-weight: 500;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: var(--fg-tertiary);
    margin-bottom: 10px;
}
.feature__title {
    font-size: 17px;
    font-weight: 600;
    margin: 0 0 8px;
    color: var(--fg);
}
.feature__body {
    font-size: 13px;
    color: var(--fg-secondary);
    line-height: 1.55;
    margin: 0;
}

/* ── Pricing strip ──────────────────────────────────────── */

.pricing {
    padding: 96px 0;
    text-align: center;
    border-top: 1px solid var(--divider);
}
.pricing .label { display: block; margin-bottom: 18px; }
.pricing__title {
    font-size: clamp(36px, 4.5vw, 52px);
    margin: 0 0 12px;
}
.pricing__price {
    font-size: 22px;
    color: var(--fg);
    margin: 0 0 8px;
}
.pricing__note {
    font-size: 13px;
    color: var(--fg-tertiary);
    margin: 0 0 28px;
}
.pricing__bullets {
    list-style: none;
    padding: 0;
    margin: 0 auto;
    max-width: 360px;
    text-align: left;
}
.pricing__bullets li {
    padding: 10px 0;
    border-bottom: 1px solid var(--divider);
    font-size: 14px;
    color: var(--fg-secondary);
    display: flex;
    align-items: center;
    gap: 12px;
}
.pricing__bullets li::before {
    content: "·";
    color: var(--fg);
    font-size: 22px;
    width: 8px;
    text-align: center;
}
.pricing__bullets li:last-child { border-bottom: none; }

/* ── Footer ─────────────────────────────────────────────── */

.footer {
    padding: 64px 0 48px;
    border-top: 1px solid var(--divider);
    text-align: center;
}
.footer__brand {
    font-family: var(--serif);
    font-style: italic;
    font-size: 22px;
    color: var(--fg);
    margin-bottom: 6px;
}
.footer__tagline {
    font-size: 12px;
    letter-spacing: 0.25em;
    text-transform: uppercase;
    color: var(--fg-tertiary);
    margin-bottom: 28px;
}
.footer__links {
    display: flex;
    justify-content: center;
    gap: 24px;
    font-size: 13px;
    color: var(--fg-secondary);
    margin-bottom: 24px;
    flex-wrap: wrap;
}
.footer__links a {
    color: var(--fg-secondary);
    border: none;
}
.footer__links a:hover { color: var(--fg); }
.footer__copy {
    font-size: 11px;
    color: var(--fg-tertiary);
    letter-spacing: 0.15em;
    text-transform: uppercase;
}

/* ── Document (privacy / support) — same theme, text-friendly ─ */

.doc {
    max-width: 760px;
    margin: 0 auto;
    padding: 24px 28px 96px;
}
.doc__head {
    padding: 48px 0 36px;
    border-bottom: 1px solid var(--divider);
    margin-bottom: 40px;
}
.doc__head .label { display: block; margin-bottom: 14px; }
.doc__head h1 {
    font-family: var(--sans);
    font-weight: 800;
    font-size: clamp(34px, 5vw, 52px);
    margin: 0 0 10px;
}
.doc__head .doc__updated {
    font-size: 12px;
    color: var(--fg-tertiary);
    letter-spacing: 0.2em;
    text-transform: uppercase;
}
.doc h2 {
    font-family: var(--sans);
    font-weight: 700;
    font-size: 24px;
    margin: 48px 0 16px;
    color: var(--fg);
}
.doc h3 {
    font-family: var(--sans);
    font-weight: 600;
    font-size: 17px;
    margin: 28px 0 10px;
    color: var(--fg);
}
.doc p, .doc li {
    color: var(--fg-secondary);
    font-size: 15px;
    line-height: 1.75;
}
.doc ul {
    padding-left: 22px;
}
.doc ul li {
    margin-bottom: 8px;
}
.doc strong { color: var(--fg); font-weight: 600; }
.doc hr {
    border: none;
    border-top: 1px solid var(--divider);
    margin: 56px 0;
}
.doc .lang-switch {
    display: flex;
    gap: 14px;
    margin-bottom: 28px;
    font-size: 12px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--fg-tertiary);
}
.doc .lang-switch a {
    color: var(--fg-secondary);
    border: none;
    padding: 6px 10px;
    background: var(--glass-fill);
    border-radius: 2px;
    border: 1px solid var(--glass-stroke);
}
.doc .lang-switch a:hover { color: var(--fg); }

/* ── Responsive ─────────────────────────────────────────── */

@media (max-width: 900px) {
    .chapter { padding: 64px 0; }
    .chapter__grid,
    .chapter:nth-child(even) .chapter__grid {
        grid-template-columns: 1fr;
        gap: 36px;
    }
    .chapter:nth-child(even) .chapter__copy { order: 1; }
    .chapter:nth-child(even) .chapter__shot { order: 2; }
    .chapter__shot img { max-width: 260px; }

    .features__grid { grid-template-columns: repeat(2, 1fr); }

    .nav { padding: 18px 22px; }
    .nav__links { gap: 16px; font-size: 12px; }
    .nav__links a:nth-child(3) { display: none; } /* hide GitHub on mobile */

    .hero { padding: 36px 0 64px; }
}

@media (max-width: 560px) {
    .features__grid { grid-template-columns: 1fr; }
    .container { padding: 0 22px; }
    .footer__links { gap: 14px; }
}